Janet Cockburn

The development and validation of a test battery for detecting and monitoring everyday memory problems

This paper describes the Rivermead Behavioural Memory Test (RMBT)-a short test of everyday memory problems with four parallel forms. It was administered to 118 control subjects aged between 16-69 years with a mean IQ of 106 (range 68-136). The limit of normal performance was established on this group and cut-off points were determined for individual components of the test. The test was also given to 176 brain-damaged people and its validity assessed both by correlating RMBT scores to performance on existing tests, to subjective ratings from patients and carers and to observation by therapists of memory lapses. Validity, parallel form and interrater reliability all proved to be high. It is concluded that the RBMT is a short, reliable, and valid test of everyday memory problems.

Cognitive motor interference while walking: A systematic review and meta-analysis

Dual-task methodology has been increasingly used to assess cognitive motor interference while walking. However, whether the observed dual-task-related gait changes are systematically related to methodological variations remains unclear and researchers still lack knowledge of what cognitive task to use in different groups for clinical purposes or for research. We systematically reviewed experimental studies that measured gait performance with and without performing concurrent cognitive task. Our results suggest that cognitive tasks that involve internal interfering factors seem to disturb gait performance more than those involving external interfering factors. Meta-analysis results show that the overall effect of different cognitive tasks was prominent in gait speed. In healthy participants, meta-regression analysis suggests strong associations between age and speed reduction under dual-task conditions and between the level of cognitive state and speed reduction under dual-task conditions. Standardizing research methodologies, as well as improving their ecological validity, enables better understanding of dual-task-related gait changes in different populations and improves, in turn, our understanding of neural mechanisms and gait control in general in content.

The behavioural assessment of visual neglect

Abstract Unilateral visual neglect is among the most striking consequences of right-sided brain damage and is characterised by the patients failure to respond to stimuli on the side contralateral to the lesion. Visual neglect disrupts many aspects of daily living such as mobility, dressing, and reading, yet the underlying mechanisms remain poorly understood. This paper describes the development, standardisation and validation of a test battery designed to identify a wide variety of visual neglect behaviours observed in clinical practice. The Behavioural Inattention Test (B.I.T.), which was standardised on a large stroke population (n = 80), is described. Unlike existing studies of visual neglect, the B.I.T. relates test results to functional assessment and rehabilitation. Using the test battery and normative data from 50 age-matched controls, 30 patients (37.5%) were classified as demonstrating neglect. Neglect is more frequent and severe following right-rather than left-sided lesions. Inter-rater, test-...

Changing patterns of cognitive-motor interference (CMI) over time during recovery from stroke

Objective: To explore the extent and nature of change in cognitive-motor interference (CMI) among rehabilitating stroke patients who showed dual-task gait decrement at initial assessment. Design: Experimental, within-subjects, repeated measures design. Setting: Rehabilitation centre for adults with acquired, nonprogressive brain injury. Subjects: Ten patients with unilateral stroke, available for reassessment 1–9 months following their participation in a study of CMI after brain injury. Measures: Median stride duration; mean word generation. Methods: Two x one-minute walking trials, two x one-minute word generation trials, two x one-minute trials of simultaneous walking and word generation; 10-metre walking time; Barthel ADL Scale score. Results: Seven out of ten patients showed reduction over time in dual-task gait decrement. Three out of ten showed reduction in cognitive decrement. Only one showed concomitant reduction in gait and word generation decrement. Conclusion: Extent of CMI during relearning to walk after a stroke reduced over time in the majority of patients. Effects were more evident in improved stride duration than improved cognitive performance. Measures of multiple task performance should be included in assessment for functional recovery.

Differential effects of age on prospective and retrospective memory tasks in young, young-old, and old-old adults

Remembering to do something in the future (termed prospective memory) is distinguished from remembering information from the past (retrospective memory). Because prospective memory requires strong self-initiation, Craik (1986) predicted that age decrements should be larger in prospective than retrospective memory tasks. The aim of the present study was to assess Craiks prediction by examining the onset of age decline in two retrospective and three prospective memory tasks in the samples of young (18–30 years), young-old (61–70 years), and old-old (71–80 years) participants recruited from the local community. Results showed that although the magnitude of age effects varied across the laboratory prospective memory tasks, they were smaller than age effects in a simple three-item free recall task. Moreover, while reliable age decrements in both retrospective memory tasks of recognition and free recall were already present in the young-old group, in laboratory tasks of prospective memory they were mostly present in the old-old group only. In addition, older participants were more likely to report a retrospective than prospective memory failure as their most recent memory lapse, while the opposite pattern was present in young participants. Taken together, these findings highlight the theoretical importance of distinguishing effects of ageing on prospective and retrospective memory, and support and extend the results of a recent meta-analysis by Henry, MacLeod, Phillips, and Crawford (2004).

Failure of prospective memory after acquired brain damage : Preliminary investigation and suggestions for future directions

This paper investigates the premise that the greater frequency of errors after acquired brain damage will facilitate identification of essential components of successful prospective memory. It examines performance by patients with recent acquired non-progressive brain damage and age-matched control subjects on two experimental measures of prospective memory. A significant different between patients and control subjects arises mainly from performance on a time-based prospective memory task. Results from patients on tests of time- and event-based prospective memory are compared with scores on tests of episodic memory and executive skills. A relationship is identified between event-based prospective memory and retrospective episodic memory but not between time-based prospective memory and executive skills. Premorbid intelligence and current mood state are identified as variables that should be considered when investigating prospective memory under experimental conditions.

Progressive Decline in Nart Score with Increasing Dementia Severity

Although the National Adult Reading Test (NART) is widely used to estimate premorbid intellectual ability in adults with possible or probable dementia, it may be less resilient to the progress of Alzheimers Disease (AD) than was initially assumed. This paper reports performance at four annual assessments of 78 people with either autopsy confirmed (n = 50) or clinical diagnosis of AD (n = 28). Results indicate that NART score does decline over time and that extent of decline is a function of MMSE score on entry to the study but is not dependent on age, education or time post onset of dementia.

Fast walking under cognitive-motor interference conditions in chronic stroke

Gait in stroke patients is often characterised by slower speeds, which may be exacerbated by situations that combine gait with a cognitive task, leading to difficulties with everyday activities. Interaction between cognitive task performance and gait speed may differ according to walking intensity. This study examines the effects of two cognitive tasks on gait at preferred walking pace, and at a faster pace, using dual-task methodology. 21 chronic stroke patients and 10 age-matched control subjects performed 2 single motor tasks (walking at preferred and at fast pace around a walkway), and two cognitive tasks (serial subtractions of 3s and a visual-spatial decision task) under single- and dual-task conditions (cognitive-motor interference) in a randomised order. Cognitive task score and gait speed were measured. The healthy control group showed no effects of CMI. The stroke group decreased their walking speed whilst concurrently performing serial 3s during both preferred and fast walking trials and made more mistakes in the visuo-spatial task during fast walking. There was no effect of walking on the serial 3 performance. The findings show that in stroke patients, during walking whilst concurrently counting backwards in 3s the cognitive task appeared to take priority over maintenance of walking speed. During fast walking whilst concurrently performing a visuo-spatial imagery task, they appeared to favour walking. This may indicate that people spontaneously favour one activity over the other, which has implications for gait rehabilitation.

How do old dogs learn new tricks: teaching a technological skill to brain injured people.

Little is known about the way people learn technological skills. This investigation was carried out to see how 100 brain injured, 50 controls and two amnesic patients performed on a task requiring them to learn a six-step programme for an electronic memory aid. Performance was correlated with other measures of memory to determine whether the technological skill was similar to a procedural learning task, a spatial memory task, a visual task, a verbal task or an amalgam of these. All controls but only 59 percent of the patients learned the task within three trials. The two amnesic patients also failed to learn the new skill. There was a high correlation between overall performance on a standardized test of everyday memory (the Rivermead Behavioural Memory Test) but little evidence that the technological skill was similar to a procedural learning task; nor was it specifically related to visual, verbal or spatial memory. It is concluded that a combination of skills is required to learn the technological task. Implications for the concept of procedural learning are discussed.

Rehabilitation for post-stroke cognitive impairment: an overview of recommendations arising from systematic reviews of current evidence

Background: Although cognitive impairments are common following stroke, there is considerable uncertainty about the types of interventions that can reduce activity restrictions and improve quality of life. Indeed, a recent project to identify priorities for research into life after stroke determined that the top priority for patients, carers and health professionals was how to improve cognitive impairments. Objective: To provide an overview of the evidence for the effectiveness of cognitive rehabilitation for patients with stroke and to determine the main gaps in the current evidence base. Methods: Evidence was synthesised for the six Cochrane reviews relating to rehabilitation for post-stroke cognitive impairment and any subsequently published randomized controlled trials to February 2012. Results: Data arising from 44 trials involving over 1500 patients was identified. Though there was support for the effectiveness of cognitive rehabilitation for some cognitive impairments, significant gaps were found in the current evidence base. All of the Cochrane reviews identified major limitations within the evidence they identified. Conclusions: There is currently insufficient research evidence, or evidence of insufficient quality, to support clear recommendations for clinical practice. Recommendations are made as to the research required to strengthen the evidence base, and so facilitate the delivery of effective interventions to individuals with cognitive impairment after stroke.